As the population grows and as traditional building methods become increasingly expensive, it has become more desirable for prospective homeowners to use prefabricated modular elements such as floor frame assemblies in building new homes. Such floor frame assemblies, with or without walls, roof, windows and doors and similar superstructure, are normally manufactured at one location and, then, towed along public highways to their ultimate destinations to be mounted on permanent supports in a safe and stable manner.
Every jurisdiction has local housing codes and standards that apply to such structures. Manufacturers, therefore, design the same to satisfy at least the Uniform Building Code (UBC). In addition to satisfying such requirements, the prefabricated structure must be transported in a safe and stable manner at highway speeds, a fact which requires that the structure being transported be capable of tolerating exposure to incidental bouncing and shock loading.
In order to reduce the overall costs to the ultimate purchaser, it is highly desirable to design the structure so that it is transported to its permanent destination in a manner that allows detachment therefrom and retrieval for reuse of any wheels and the towing hitch assembly that were utilized during transportation. Although considerable work has been done in the field of this invention in meeting the needs outlined hereinabove as exemplified in my own patents, U.S. Pat. Nos. 3,716,267, 4,015,375, 4,106,258, 4,019,299 and 4,863,189, all of which are incorporated herein by reference, there still exists a need for an improved towable unified floor frame assembly that satisfies the UBC, is easily and safely transportable to its ultimate destination and from which the towing wheels and towing hitch elements can then be readily detached and retrieved for reuse.
In particular, there is an unfulfilled need for large unified modular floor frame assemblies in lengths of 60 ft. or more and widths of 18 ft. to 20 ft. Such assemblies are not easy to construct by conventional techniques to the strengths needed to support the floor loading often encountered in homes or offices with heavy furniture, file cabinets, or office equipment. Furthermore, especially where such flooring is utilized to construct homes, homeowners and home designers often desire the floor-planning flexibility of step-down floor portions to define different regions in a given room, e.g., a sunken living area approachable from a hallway or entrance, a sunken area for a bedroom to be provided with an overhead fan, and the like. To satisfy such needs, particularly for modular construction with its inherent advantages of tight quality control, economies of scale, and consistency of strength and structural dimensions, the use of wooden I-beams provides unique and nonobvious advantages over known alternatives.
Another advantage of using I-beams as joists, i.e., as transverse floor supporting members in place of conventional trusses is that a floor of exceptional width can be provided to the requisite strength yet with a small vertical dimension. This allows construction of a complete housing structure thereon in a form readily transportable on highways and under overpasses that are encountered in transporting modular homes.
The present invention satisfies all these needs at a relatively low cost because it significantly reduces the amount of metal, typically steel, that is left in the unified floor frame assembly after it is delivered to its destination. Wood is a renewable resource, unlike metal, and the reduction in use of metal made possible by this invention thus has the additional incidental benefits of lowering costs, conserving non-renewable resources, and reducing atmospheric pollution as is incidental to steel manufacture.